Xcalibre (CD Version)

Xcalibre - User-friendly IRT Calibration Click here to see a comparison of all Analysis Programs Xcalibre represents an improved approach to the challenge of IRT item parameter estimation. A significant amount of attention has been directed at marginal maximum-likelihood estimation methods for obtaining IRT parameter estimates. Accurate estimation of IRT item parameters using maximum-likelihood approaches, including Bayesian techniques, tend to require longer tests and larger sample sizes. A generally accepted guideline for obtaining reasonable item parameter estimates with maximum-likelihood techniques is at least 50 items and 1,000 examinees (for a 3-parameter IRT model). Using marginal maximum-likelihood estimation, Xcalibre can provide accurate item parameter estimates with fewer examinees and shorter tests. Features Point-and-click interface; no special coding language required! Able to estimate both 2- and 3-parameter IRT item parameters; Works with very large data sets; Floating priors: Xcalibre implements Bayesian prior distributions on the individual item parameters, but these prior distributions may be allowed to be updated during the estimation process; "Fixing" items: Common (anchor) items in a larger data set may be "fixed" to specified parameter values (from a previous estimation run). Fixing selected item parameters results in automatic linking of the remaining item parameters onto the target (common) scale; Evaluation of the fit of each item to the IRT model is provided; and Works with incomplete data sets and can differentiate between items that are omitted and those that were not attempted. Review of Xcalibre Read the review of Xcalibre which was published in the journal Applied Psychological Measurement, Vol. 20, No. 3, September 1996, pp. 303-307. Reprinted by permission. Specifications Xcalibre can analyze up to 750 items with no limit on the number of examinees. System Requirements Windows 95, 98, NT, ME, 2000, XP, Vista, Windows 7 Trial Version This trial version of Xcalibre is fully functional, but time limited to 7 days operation. This version can be converted to the commercial version by email, fax, or phone after payment arrangements have been completed. Download the Xcalibre Trial (8.80MB) This is the Xcalibre manual in PDF format. Download it for operation instructions and more information. Download the Xcalibre Manual (458 KB) Test Analysis Package Xcalibre is also available as part of the Item and Test Analysis Package. Books about Item Response Theory and Related Methods Applications of Item Response Theory to Practical Testing Problems Essays on Item Response Theory Explanatory Item Response Models Fundamentals of Item Response Theory Handbook of Modern Item Response Theory Item Response Theory for Psychologists Item Response Theory: Parameter Estimation Techniques Item Response Theory: Principles and Applications Test Scoring The EM Algorithm and Related Statistical Models To Purchase This Product   To purchase the download version, click here to go to the download purchase page To purchase the CD version, use 'Order Options and Details' below. Order Options and Details   License Please Select Software Package Xcalibre - Academic (Shipped on CD) Xcalibre - Non-Academic (Shipped on CD) Quantity 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Weight 0.40 lbs Price: $0.00  Add to cart

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